Suleman Dawood took a Rubik's Cube with him onboard the doomed Titanic sub in order to break a Guinness World Record. The 19-year-old's mother, Christine Dawood, spoke with BBC about what he had hoped to achieve before a catastrophic implosion killed all five passengers onboard the Titan submersible. [readmore label="READ MORE: " link="https://etcanada.com/news/1001660/titanic-sub-families-pay-emotional-tribute-to-5-passengers-killed-in-catastrophic-implosion/" /] "He…